The behavior of H ion-implanted crystalline material was investigated, at the ns time-scale and at temperatures up to the melting point, by using pulsed laser annealing. Laser reflectivity, scanning electron microscopy, and surface profilometry methods were used to characterize the implantation and annealing effects. Computer modelling of H release, as a function of laser energy, was used to interpret the data. Desorption of H which had been implanted at 1 or 2keV occurred at temperatures above 1000K, with no extensive surface deformation. This desorption could be fitted to de-trapping curves by using an activation energy (of about 2eV) that slowly decreased for H/Si ratios which ranged from 0.04 to 0.27. Contrary to expectation, no diffusion limitation was observed. When implanted at 5 or 10keV, for H/Si ratios greater than 0.2, H was released at temperatures greater than 550K (via blister rupture). It was found that, in spite of differences between the effects of low and high implantation energies, a unified picture emerged which posited the existence of a layer with a high-temperature H mobility that was greater than that of ordinary atomic diffusion.

R.Boivin, B.Terreault: Journal of Applied Physics, 1993, 73[4], 1943-51